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101.
102.
Ryoko?M.?Uda Toshihiro?Matsui Masatoshi?Oue Keiichi?KimuraEmail author 《Journal of inclusion phenomena and macrocyclic chemistry》2005,51(1-2):111-117
Photoirradiation effect on potential response to metal ion concentrations and photoinduced potential change were investigated with poly(vinyl chloride) membranes based on a Malachite Green derivative carrying a bis(monoaza-15-crown-5) moiety, by comparing other Malachite Green derivatives. The Malachite Green carrying a bis(crown ether) moiety caused a potential response to potassium ion concentration changes under dark condition. In the membrane potential response, a clear-cut photoinduced switching of potential response was realized by the membrane of Malachite Green carrying a bis(crown ether) moiety, which exhibited no potential response to potassium ion concentrations (0 mV/decade) on UV irradiation. On the other hand, a Malachite Green carrying a monocyclic benzocrown ether moiety showed a considerable dependence of the membrane potential on the metal ion concentrations under both dark and UV irradiation conditions.This revised version was published online in July 2005 with a corrected issue number. 相似文献
103.
O-Glycans (mucin type oligosaccharides) are ubiquitously found in various glycoproteins such as mucin-type glycoproteins on the surface of various digestive organs. In the present paper, we propose a method for detecting O-glycanase which catalyzes the hydrolysis of the O-glycan linkage between oligosaccharides and serine/threonine residues of mucin-type glycoprotein. As the substrate for O-glycanases, we chose glycopeptides containing O-glycans derived from bovine fetuin. The present method is divided into two parts. At the initial stage, the presence of O-glycanase was confirmed by observing characteristic ions due to O-glycans and peptides released from the glycopeptide by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. In the second step, europium labeled O-glycosylated peptide permits more detailed analysis such as enzyme kinetics. We demonstrated the usefulness of the present method using O-glycanase (Streptococcus pneumoniae) as model enzyme. The present approach can easily confirm the presence of O-glycanase by detecting both deglycosylated peptides and O-glycans, even if contaminating peptides or glycosidases are present in crude biological samples. 相似文献
104.
Yamada K Nomura Y Citterio D Iwasawa N Suzuki K 《Journal of the American Chemical Society》2005,127(19):6956-6957
A non-PET and non-PCT fluoroionophore has been designed and synthesized based on the combination of a biaryl boron-dipyrromethene fluorophore with an oligoethyleneglycol bridge. A specific red-shift response of absorption for NaClO4 in acetonitrile was demonstrated based on conformational restriction triggered by cation recognition at the bridge. The concentration of Na+ can be determined accurately using fluorescence due to a high extinction coefficient (epsilon = 50 000), a high fluorescence quantum yield (Phif = 0.68), and the sharpness of absorption and emission peaks of the boron-dipyrromethene derivative. 相似文献
105.
Takao Mori Ryujiro Sano Yasuo Iwasawa Tetsuya Tosa Ichiro Chibata 《Applied biochemistry and biotechnology》1976,1(1):15-26
Conditions for the preparation of an asparaginase (L-asparagine amidohydrolase, EC 3.5.1.1) tube using polyacrylamide gel were investigated. The apparent yield of activity of the asparaginase tube was about 20%; the activity of the tube was dependent on inner surface area. The optimum pH of the asparaginase tube shifted by 1 pH unit to the acid side in comparison with that of native enzyme. The apparent Michaelis constant of the tube was about 200 times higher than that of the native enzyme. The half-life of the asparaginase tube in continuous operation was estimated to be 16 days at 37°C. The tube was found to be resistant to attack by proteolytic enzyme. The L-asparagine level in blood plasma of a dog was lowered to 1/4 by the performance of an extracorporeal shunt using the asparaginase tube. 相似文献
106.
Shindo K Osawa A Nakamura R Kagiyama Y Sakuda S Shizuri Y Furukawa K Misawa N 《Journal of the American Chemical Society》2004,126(46):15042-15043
The comprehensive bioconversion of aromatic compounds with a benzene ring to a picolinic acid was achieved with a recombinant Escherichia coli strain that expressed the six genes involved in biphenyl catabolism, these being the bphA1(2072)A2A3A4 genes encoding the evolved biphenyl dioxygenase, the bphB gene encoding dihydrodiol dehydrogenase, and the bphC gene encoding catechol 2,3-dioxygenase. 相似文献
107.
Aoki M Kaneko M Izumi S Ukai K Iwasawa N 《Chemical communications (Cambridge, England)》2004,(22):2568-2569
Novel bidentate amidines were designed and synthesized as easily available electron-donating N-ligands for Ni0-mediated coupling of carbon dioxide with alkynes or allenes, and high regioselectivity was achieved even for the carboxylation of aryl substituted internal alkynes. 相似文献
108.
Zeolite-supported rhenium catalysts are active for selective oxidation of benzene with molecular oxygen, where coexisting ammonia is prerequisite to the direct phenol synthesis. 相似文献
109.
Choudary BM Madhi S Kantam ML Sreedhar B Iwasawa Y 《Journal of the American Chemical Society》2004,126(8):2292-2293
The design and synthesis of surface transient organometallic intermediates on nanopalladium supported on layered double hydroxides is conceived and developed for the first time. The formation of only one STO intermediate in all the Heck-, Suzuki-, Sonogashira-, and Stille-type coupling reactions during their reaction sequences and the excellent isolated yields of each of the coupling products from the corresponding organometallic complexes not only validate the mechanism but also demonstrate the evolution of the single-site heterogeneous catalyst. 相似文献
110.
Reflectance, transmittance and absorbance spectra were observed of Hydrobryum japonicum, a kind of Aquatic angiosperm, over the wavelength range from 300 to 780 nm. Three remarkable peaks were observed at 380, 430, and at 680 nm in the absorbance
curve, which were assigned to the two pigments flavonoid and chlorophyll. The functions of these pigments of making photosynthesis
inevitable for the botanical activity and of protecting the plant from the heat given by the sunlight were discussed. 相似文献